A new synthetic method of coumestan derivatives

Zusammenfassung Die Synthese von 7-Hydroxy-5,6-dimethoxybenzofurano[3,2:3,4]coumarin aus 7,2-Dihydroxy-oder 7-Benzyloxy-2-hydroxy-4,5-dimethoxyisoflavon wird beschrieben.     

Fever produced in rabbits by N6, O2′-dibutyryl adenosine 3′, 5′-cyclic monophosphate

Zusammenfassung Die Injektion von N⁶-2-O-Dibutyryl-adenosin-3 5-monophosphat in den lateralen Hirnventrikel von Kaninchen führt zu einer langanhaltenden Fieberreaktion, was vermuten lässt, dass zyklisches Adenosin-35-monophosphat als weiterer Mediator in der Genese des Fiebers fungiert.     

The syntheses of axillarin and its related compounds

Zusammenfassung Axillarin (5, 7, 3, 4-Tetrahydroxy-3,6-dimethoxyflavon). 5,3,4-Trihydroxy-3,6,7-trimethoxyflavon und 5,7,3,4-Tetrahydroxy-3,8-dimethoxyflavon wurden synthetisiert.     

Total synthesis of orellinine,a minor toxic component of the fungusCortinarius orellanus fries

Summary The 3,3,4,4-tetrahydroxy-2,2-bipyridyl-N-oxide has been synthesized by dealkylation of the corresponding tetramethyl derivative. The chemical properties of this compound are identical to those reported for the minor fungal toxin ofCortinarius orellanus, orellinine.This work is part of the Tesi di Laurea of Miss Cinzia Pierucci.     

Separation of rat liver mitochondrial amine oxidases

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The selective esterification of the 5′-hydroxyl of thymidine

Zusammenfassung Ein einfacher Weg zur selektiven Esterbildung mit der 5-Hydroxylgruppe von Thymidin wird beschrieben. Beispiele: Thymidin-5-phosphat, Thymidin-5-sulfat und Thymidin-5-trichloracetat.     

Hotspots of homologous recombination

Homologous recombination occurs at higher than average frequency at and near hotspots. Hotspots are special nucleotide sequences recognized by proteins that promote, directly or indirectly, a rate limiting step of recombination. This review focuses on two well-studied examples, the Chi sites of the bacteriumEscherichia coli and the M26 site of the fission yeastSchizosaccharomyces pombe. Chi, 5 G-C-T-G-G-T-G-G 3, is recognized by the RecBCD enzyme, which nicks the DNA near Chi and produces a 3-ended single-stranded DNA tail; this tail is a potent substrate for homologous pairing by RecA and single-stranded DNA binding proteins. M26, 5 A-T-G-A-C-G-T 3, is recognized by a heterodimeric protein and stimulates, by an as-yet-unknown mechanism, meiotic recombination at and near theade6 gene. Additional hotspots in bacteria, fungi, and mammals enhance recombination directly or indirectly via a variety of mechanisms. Although hotspots are widespread among organisms, the biological role of their localized enhancement of recombination remains a matter of speculation.     

Synthesis of dinucleoside phosphates by reaction of 5′-chloro-5′-deoxynucleosides with nucleotide anions

Zusammenfassung Uridylyl-(3–5)-adenosin und Uridylyl-(3-5)-ionosin wurden durch Umsetzung eines passenden 5-chloro-5-deoxy-2, 3-O-isopropylidene-Nukleosids mit Uridin-3-phosphat synthetisiert.     

Bemerkungen zur Struktur des Capsorubins

Summary By oxidative degradation of capsorubin, it could be demonstrated that the methyl groups are in position 1, 1, 5 (1, 1, 5) and the OH-group is attached to carbon atom 3 (3). An analogous structure may be assumed for capsanthin and cryptocapsin.     

Cardenolide glycosides from the adults and eggs ofChrysolina fuliginosa (Coleoptera: Chrysomelidae)

Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by¹H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.     

The synthesis of isohalfordin

Zusammenfassung Die Synthese von Isohalfordin (3,4, 8-Trimethoxyfuro[3,2:6, 7]cumarin) aus 6,7-Dihydroxy-2, 3-dihydrobenzo[b]furan wird beschrieben.     

Polyhydroxylated metabolites oftrans-stilbene in the rat

Zusammenfassung Nach Eingabe vontrans-Stilben bei Ratten wurden die grössten Mengen im Harn als 3,4,4-Trihydroxystilben, 3,4,4-Trihydroxybibenzyl und 3,3, 4,4-Tetrahydroxybibenzyl nachgewiesen. Die Bibenzylderivate werden nachscheinlich nach Ausscheidung in der Galle von Darmbakterien metabolisiert.     

The effect of cyclic N-2-O-dibutyryl-adenosine-3′, 5′-monophosphate on neuromuscular transmission and concentration of glycogen in the isolated phrenic nerve-diaphragm preparation of the rat

Résumé Le dérivé dibutyrique du 3, 5-AMP cyclique potentialise les contractions du diaphragme provoquées par stimulation électrique indirecte, alors que l'application du 3,5-AMP cyclique n'a pas un tel effet. D'autre part, ce dérivé diminue le taux de glycogène du diaphragme, ce qui n'est pas le cas pour le 3,5-AMP cyclique.     

The synthesis of toxicarol isoflavone

Zusammenfassung Die Synthese von Toxicarol Isoflavon (2, 2-Dimethylpyrano(6, 5: 7,8)-5-hydroxy-2,4 5-trimethoxyisoflavon) aus 2,2-dimethyl-5-hydroxy-7-methoxychroman wird beschrieben.     

Die Induktion lysogener Bakterien durch Nitrosamide

Summary N, N-dinitroso-N, N-dimethyloxamide and N, N-dinitroso-N, N-dimethylterephtal acid amide, both mutagenic for yeast cells, induce phage production by lysogenicEscherichia coli K12 () cells.     

The effect of chloramphenicol analogs on protein biosynthesis in a cell-freeEscherichia coli B system

a aaa a aa aa a a E. coli aa, a aa aa a , a a aa - a .

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Laboratory of Biological Investigations.

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Laboratory for Chemistry of Antibiotics.     

Brominated diphenyl ethers from a marine bacterium associated with the spongeDysidea sp.

Summary BacteriaVibro sp. isolated from the spongeDysidea sp. were shown to biosynthesize brominated diphenyl ethers. We identified one of the bacterial brominated metabolites using gas liquid chromatography and mass spectrometry to compare this product with standard 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol. The latter has been isolated from ethanol extracts of the spongeDysidea sp.     

2,2′-dihydroxy-6,6′-dinaphthyl disulphide (DDD) diazo blue B reactive granules in the parathyroid gland of the rat and toad

Zusammenfassung Granula in Parenchymzellen von Ratten und Kröten-Epithelkörperchen treten durch 2,2-Dihydroxy-6,6-dinaphthyl-disulfid (DDD) Diazo-Blau-B-gefärbt, deutlich hervor. Ihre Menge, Färbbarkeit und Verteilung unter verschiedenen Bedingungen scheinen für die zelluläre Sekretionstätigkeit charakteristisch zu sein.     

The red impurity in trypan blue

Zusammenfassung Isolierung und Strukturaufklärung der roten Komponente des teratogenen und karzinogenen Farbstoffs Trypanblau: 8-ammo-2-(3, 3-Dimethylbiphenyl-4azo)-naphth-1-ol-3,6-Disulphonsäure.